Free Audio to MIDI Conversion — A Complete Guide Using Just Your Browser
Audio to MIDI Conversion: Can You Really Do It for Free? The Short Answer
"I want to turn a guitar riff I recorded into MIDI." "I hummed a melody — can I get it into a piano roll?" "I recorded a performance and want to edit it in my DAW." — These are the kinds of questions that lead people to search for Audio to MIDI conversion.
Here's the bottom line: as of 2024, you can convert audio to MIDI entirely in your browser — no installation, no cost. AI models like Basic Pitch, developed by Spotify's research team, now run directly in the browser, making it possible to generate MIDI tracks from audio files without any dedicated software.
In this guide, we'll cover everything from how Audio to MIDI conversion works, to step-by-step instructions, to tips for specific sound sources like guitar, whistling, and humming.
How Audio to MIDI Conversion Works — AI Analyzes Pitch and Converts It to MIDI
Audio to MIDI conversion is the process of analyzing the pitch, timing, and dynamics of an audio file and outputting corresponding MIDI notes. In the past, this required paid software like Melodyne. But in recent years, deep learning–based models have emerged, dramatically improving both accuracy and speed.
Monophonic vs. Polyphonic Conversion
There are two main types of Audio to MIDI conversion:
- Monophonic conversion: Designed for instruments that play one note at a time — flute, whistling, lead vocals. High accuracy and fast processing.
- Polyphonic conversion: Handles instruments that produce multiple simultaneous notes — guitar chords, piano. More complex, and results vary more depending on the AI model used.
Single-note melodies like whistling or humming convert with very high accuracy — even beginners tend to get great results. Polyphonic sources like guitar chords may require some manual cleanup in the piano roll after conversion.
Leading Audio-to-MIDI Engines
- Basic Pitch (Spotify): Free, browser-based. Runs inference locally using an ONNX model. High accuracy with polyphonic support.
- Melodyne (Celemony): The industry-standard paid tool. Best-in-class accuracy, but starts around $100+ for the Essential edition.
- ARA (Celemony): DAW plug-in version of Melodyne. Integrates directly into hosts like Studio One.
- MIDI-DDSP (Magenta): A Google research project that converts audio to MIDI while preserving instrument-specific expression.
Step-by-Step: Free, Browser-Based Audio to MIDI Conversion with Basic Pitch
The easiest free method is to use the built-in Basic Pitch engine inside LA Studio (a browser-based DAW). Since conversion and MIDI editing happen in the same interface, there's no need to move files between apps.
Step 1: Prepare Your Audio File
Supported formats include WAV, MP3, OGG, FLAC, and other common audio formats. Have your recorded performance file ready.
- Shorter clips — around 8 to 32 bars — tend to convert with higher accuracy
- Less background noise means better results. If needed, run the file through AI noise removal first
- For vocals or whistling mixed with backing tracks, accuracy drops significantly. Use vocal removal / stem separation to isolate the melody first
Step 2: Run Audio to MIDI Conversion in LA Studio
- Open https://la-studio.cc/editor in your browser — no sign-up or installation needed
- Drag and drop your audio file into the playlist to create an audio region
- Right-click (or long-press) the region to open the context menu
- Select "Audio to MIDI (Basic Pitch)" from the menu
- The ONNX model runs inference locally in your browser — processing takes anywhere from a few seconds to half a minute
- Once complete, a MIDI region is automatically placed on a new track in the playlist
- Double-click the MIDI region to open the piano roll and review the results
Step 3: Fine-Tune in the Piano Roll
AI conversion isn't perfect, so check for the following:
- Remove noise notes: Delete unintended short notes caused by articulation noise or artifacts
- Quantize timing: Use the quantize function to snap notes to the nearest grid position
- Adjust velocity: Check that dynamics are represented well and tweak individual note velocities as needed
- Check for octave errors: Occasionally notes land an octave off — listen back and correct as needed
Step 4: Export as a MIDI File
- Close the piano roll when you're done editing
- Right-click the MIDI region and select "Export MIDI"
- The file downloads as an SMF (Standard MIDI File)
- The exported MIDI file can be imported into any DAW — Cubase, Logic Pro, FL Studio, Ableton Live, and more
Tips and Gotchas by Sound Source
Guitar — Single-Note Lines
Guitar solos and single-note riffs convert with high accuracy in Basic Pitch. Keep these tips in mind:
- Record with minimal distortion. Clean or crunch tones have more controlled harmonics and convert more accurately than heavily distorted signals
- Bends and vibrato cause continuous pitch fluctuation, which can result in the note being split into many small fragments. Manual cleanup in the piano roll is usually needed
- Harmonics may be detected two or three octaves higher than intended — double-check those passages
- Once you have the MIDI in your DAW, swapping it to a synth or piano sound is a great way to turn a guitar performance into a keyboard part
Guitar — Chords and Polyphonic Playing
Strummed chords are the most challenging material for Audio to MIDI conversion.
- Basic Pitch does support polyphonic input, but complex chord voicings are prone to missed notes or false detections
- After conversion, prioritize checking that the chord's core tones (root, third, fifth) came through correctly
- Arpeggios convert more accurately than strummed chords, since the notes are more separated in time
Whistling, Humming, and Singing
Whistling and humming are ideal candidates for Audio to MIDI conversion — they're monophonic with relatively simple harmonic content. This is the most practical approach when you want to quickly capture a melody idea as MIDI.
- Record in a quiet environment using a microphone, or use your phone's voice memo app and load the file into your browser
- Singing or humming along to a metronome makes it much easier to snap notes to the grid afterward
- Some browser DAWs offer a "Voice to MIDI" feature for real-time conversion while recording directly in the browser
- LA Studio includes a built-in Voice to MIDI function that records your voice and converts it to a MIDI track on the fly
Bass, Cello, and Other Low-Register Instruments
- Basic Pitch is slightly less reliable in the low frequency range — always verify the octave setting after conversion
- Sub-bass content below 60 Hz is often missed entirely. Boosting 80 Hz and above with EQ before conversion can help
- Fretless bass and slide playing generate a lot of glide, which can result in a large number of pitch bend events in the converted MIDI
5 Tips to Improve Audio to MIDI Conversion Accuracy
- Remove noise beforehand: Background hiss and ambient noise reduce AI detection accuracy. Run the file through AI noise removal before converting
- Use isolated instrument tracks: Drums and other instruments mixed in will cause false detections. Use stem separation to extract just the instrument you want to convert
- Record at 44.1 kHz or higher: Low-quality audio negatively impacts the model's inference quality
- Break long recordings into short segments: Converting 8–16 bar chunks at a time makes it much easier to review and correct the output
- Always review in the piano roll: Think of AI conversion as a first draft. The final musical result still needs a human touch to get right
What Is Basic Pitch? An Overview of Spotify's Free AI Engine
Basic Pitch is an open-source Audio-to-MIDI model published by Spotify's research team in 2022. The paper demonstrated significantly higher accuracy compared to traditional DSP-based approaches, with particular strength in handling polyphonic instruments like guitar and piano.
The model runs in the browser via WebAssembly and ONNX Runtime Web, which means your audio data never leaves your device. Everything is processed locally — an important advantage for privacy and security.
What to Do with Your MIDI After Conversion
Once you have MIDI data from an audio source, there are plenty of creative ways to take it further.
Route It to a Software Synthesizer
Assign the converted MIDI track to a soft synth — LA Studio supports instruments like Vital, Surge XT, and Dexed — and instantly transform a guitar riff into a synth lead or pad sound.
Analyze Chords and Explore New Arrangements
MIDI chords extracted from a polyphonic recording can be analyzed to reveal the chord progression, which you can then use as the basis for a new arrangement. It's also a great technique for reharmonizing existing songs.
Export to Your DAW of Choice
Export an SMF file from LA Studio and import it into Cubase, Logic Pro, Ableton Live, FL Studio, Studio One, or any other DAW to continue working in your preferred environment.
Frequently Asked Questions
Q. Is Audio to MIDI conversion fully automatic?
A. The conversion process itself is automated by AI, but the results aren't always perfect. Polyphonic sources like guitar chords almost always require some manual cleanup in the piano roll. Single-note melodies — whistling, humming, flute — convert with much higher accuracy and are often usable with little or no editing.
Q. What audio formats are supported?
A. LA Studio's Basic Pitch conversion supports WAV, MP3, OGG, FLAC, and other common formats. If you have an M4A file recorded on your phone, we recommend converting it to MP3 or WAV before loading it in.
Q. Can drums and percussion be converted to MIDI?
A. Basic Pitch is a pitch detection–based engine, so it's not well suited for drums and unpitched percussion. Converting drum sounds accurately requires onset/transient detection algorithms rather than pitch tracking. For drum patterns, programming directly in the piano roll will give you more reliable results.
Q. Can I import the converted MIDI into Cubase or Logic Pro?
A. Yes. LA Studio exports standard SMF (Standard MIDI File) format, which is compatible with virtually every DAW — Cubase, Logic Pro, Ableton Live, FL Studio, Studio One, and more.
Q. Is my audio uploaded to a server during conversion?
A. No. LA Studio's Basic Pitch conversion runs entirely within your browser using the ONNX runtime. Your audio data is never sent to any server, so your files stay private and secure.
Conclusion: Audio to MIDI Conversion Is Now Free and Browser-Based
What once required expensive dedicated software can now be done for free, right in your browser, thanks to AI engines like Basic Pitch from Spotify. Single-note sources like whistling and humming convert with impressive accuracy, and single-note guitar lines produce very usable results as well.
LA Studio, a browser-based DAW, offers completely free, installation-free Audio to MIDI conversion powered by Basic Pitch — covering everything from conversion to piano roll editing to MIDI export, all in one place. You can start using it right now with no account or download required.